The development of forms and functions of aggression during early childhood: A temperament-based approach.

This study used a short-term longitudinal design with theoretically derived preregistered hypotheses and analyses to examine the role of temperament in the development of forms (i.e., physical and relational) and functions (i.e., proactive and reactive) of aggressive behavior in early childhood (N = 300, M age = 44.70 months, SD = 4.38, 44% girls). Temperament was measured via behavioral reports of emotional dysregulation, fearlessness/daring, and rule internalization/empathy and, in a subsample that completed a physiological assessment, via skin conductance and respiratory sinus arrhythmia. Emotion dysregulation generally served as a risk factor for all subtypes of aggression, with evidence of stronger associations with reactive as compared to proactive functions of relational aggression for girls. Daring predicted increases in physical aggression, especially among boys, and rule internalization predicted decreases in relational aggression, especially among girls. Rule internalization mediated longitudinal associations between daring and proactive relational aggression for girls. Some evidence also emerged supporting associations between adaptive functioning (i.e., high empathy, high respiratory sinus arrhythmia) and proactive functions of aggression. Findings highlight distinct temperamental risk factors for physical versus relational aggression and provide partial support for gender-linked theories of the development of aggression.

Aggression and Irritability in Middle Childhood: Between- and Within-Person Associations.

OBJECTIVE: This study tested predicted bidirectional associations between irritability and physical and relational forms of aggression, disentangling theorized within- and between-person effects using latent curve models with structured residuals (LCM-SR) over one year in middle childhood. Gender differences and robustness of results when controlling for other externalizing problems (i.e., attention problems, delinquency) were also considered. METHOD: Children in third, fourth, and fifth grade (N = 704, 49.9% female) were recruited from schools in a large midwestern city. The sample was diverse in regard to race/ethnicity (31% Black, 29% White, 13% Hmong, 14% Latinx, 4% Native American, 4% Asian, 5% other races/ethnicities). Irritability, attention problems, and delinquency were measured using teacher-report, and physical and relational aggression were measured using self-report at three time points over one calendar year. RESULTS: At the between-person level, higher mean levels of irritability predicted higher initial levels of physical and relational aggression. Irritability continued to predict higher levels of physical aggression across the course of the study, whereas the effect of irritability on relational aggression diminished. Boys showed higher starting levels of physical aggression, but no other significant gender differences emerged. No significant within-person associations were found. CONCLUSIONS: The present study suggests that irritability may represent a between-person risk factor for high levels of physical and relational aggression in middle childhood, although effects on physical aggression may be more persistent. This highlights the importance of considering affective processes to understand the development of aggression trajectories.

Prenatal substance exposure, early-life adversity, and parenting: Associations with adolescent stress response.

We tested a conceptual model examining associations between prenatal substance exposure and adolescent cortisol reactivity profiles in response to an acute social evaluative stressor. We included cortisol reactivity in infancy, and direct and interactive effects of early-life adversity and parenting behaviors (sensitivity, harshness) from infancy to early school age on adolescent cortisol reactivity profiles in model testing. Participants were 216 families (51% female children; 116 cocaine-exposed) recruited at birth, oversampled for prenatal substance exposure, and assessed from infancy to early adolescence (EA). Majority of participants self-identified as Black (72% mothers, 57.2% adolescents), and caregivers were primarily from low-income families (76%), were single (86%), and had high school or below education (70%) at recruitment. Latent profile analyses identified three cortisol reactivity patterns including elevated (20.4%), moderate (63.1%), and blunted (16.5%) reactivity groups. Prenatal tobacco exposure was associated with higher likelihood of membership in the elevated reactivity compared to the moderate reactivity group. Higher caregiver sensitivity in early life was associated with lower likelihood of membership in the elevated reactivity group. Prenatal cocaine exposure was associated with higher maternal harshness. Interaction effects among early-life adversity and parenting indicated that caregiver sensitivity buffered, and harshness exacerbated, the likelihood that high early adversity would be associated with the elevated and blunted reactivity groups. Results highlight the potential importance of prenatal alcohol and tobacco exposure for cortisol reactivity and the role of parenting as exacerbating or buffering the impact of early-life adversity on adolescent stress response.

Trajectories of physical and relational aggression across early childhood: Relations with peer risk factors.

The goal of the current study was to examine trajectories of relational and physical aggression in early childhood and evaluate peer predictors of these trajectories (i.e., peer rejection, relational victimization, and physical victimization). The study spanned three-time points (T1 in the spring, T2 in the fall, and T3 in the spring) in early childhood (N = 300; 44.0% girls; Mage = 44.70 months, SD = 4.38; 3.0% African American/Black, 7.6% Asian/Asian American/Pacific Islander, 1.0% Hispanic/Latinx, 11.3% multiracial, 62.1% White, and 15.0% missing/unknown). Observations of peer victimization and teacher report of peer rejection were collected at T1, and teacher report of aggression was collected at all time points. Results from piecewise latent growth models demonstrated that both forms of aggression decreased from T1 to T2 as children entered a new classroom and increased from T2 to T3 as they remained in that classroom. The increase in physical aggression from T2 to T3 was only significant for boys. Peer rejection at T1 emerged as a predictor of both intercepts and slopes from T1 to T2, and physical victimization predicted the physical aggression intercept and physical aggression slope from T1 to T2. Children high on these peer risk variables had higher initial levels of aggression, followed by a greater decrease in aggression from T1 to T2. Results underscore the importance of studying incremental change in aggression in early childhood and suggest that children who experience negative peer treatment have greater fluctuations in aggression over time.

Inhibitory Control in Early Childhood Aggression Subtypes: Mediation by Irritability.

The present study tested irritability as a mediator of inhibitory control's (IC) associations with crossed form and function aggression subtypes over one year in early childhood (N = 300, Mage = 44.70 months, SD = 4.38 months). We hypothesized lower IC would predict increases in irritability, which would in turn predict increases in aggression overall (severity) and a predominance of reactive over proactive subtypes (directionality), and considered moderation by gender. Irritability mediated IC's relations in the predicted direction for physical severity for girls only and relational severity for both genders. Lower IC predicted increases in irritability, which in turn predicted increasing predominance of reactive over proactive physical and relational aggression. The predicted indirect effect was significant for physical but not relational directionality. Findings highlight the viability of directionality scores for disentangling these effects, and that developmental associations between IC, irritability, and reactive functions of aggression are evident in early childhood.

Relational Victimization, Characterological Self-Blame, and Adjustment in Young Children.

The associations between relational victimization, self-blame attributions, and internalizing problems in early childhood has not previously been examined. Using a sample of 116 preschool children, average age 44.05 months (SD = 4.23), multiple informants, multiple methods, and a longitudinal design, path analyses were conducted to explore the associations between relational victimization, self-blame attributions (Characterological Self-Blame[CSB] and Behavioral Self-Blame[BSB]), and maladjustment in early childhood. Concurrent significant associations were found between relational victimization and internalizing problems. The initial longitudinal models revealed some significant effects that were consistent with predictions. Importantly, follow-up tests decomposing internalizing problems, indicated that anxiety at Time 1 was positively and significantly associated with CSB at Time 2. Depression at Time 1 was negatively and significantly associated with CSB at Time 2. Implications of this work are discussed.

Stress reactivity and social cognition in pure and co-occurring early childhood relational bullying and victimization.

This study tested the independent effects and interactions of sympathetic nervous system reactivity and hostile attribution biases (HAB) in predicting change in pure and co-occurring relational bullying and victimization experiences over one year. Co-occurring and pure relational bullying and victimization experiences were measured using a dimensional bifactor model, aiming to address methodological limitations of categorical approaches, using data from 300 preschoolers (Mage = 44.70 months, SD = 4.38). Factor scores were then saved and used in nested path analyses with a subset of participants (n = 81) to test main study hypotheses regarding effects of HAB and skin conductance level reactivity (SCL-R). Bifactor models provided good fit to the data at two independent time points. HAB and SCL-R interacted to predict increases in co-occurring relational bullying/victimization with evidence for over- and underarousal pathways.

Autonomic nervous system reactivity and preschoolers' social dominance.

The purpose of this study was to investigate the role of skin conductance level reactivity (SCLR) and respiratory sinus arrhythmia reactivity (RSAR) in preschoolers' social dominance, as well as potential gender differences in these associations. Reactivity was assessed in response to viewing videos of social exclusion and a post-aggression discussion. In a community sample of 94 preschool children followed over one calendar year, reactivity to the post-aggression discussion, but not exclusion, video was related to social dominance. Specifically, increased RSAR to the post-aggression discussion video was positively associated with concurrent social dominance for both boys and girls. Longitudinally, for boys only, coactivation (i.e., increases in SCLR accompanied by increases in RSAR) to the post-aggression discussion video, which may reflect dysregulated, emotionally labile reactions to stress, was associated with relatively low levels of social dominance across the course of the year. Overall, findings contribute to a growing literature documenting the role of autonomic reactivity in preschoolers' social adjustment and extend this work to their capacity to achieve and maintain socially dominant positions with peers.

Developmental Pathways from Prenatal Substance Exposure to Reactive Aggression.

Few studies have examined etiological pathways from prenatal substance exposure to adolescent reactive aggression. We tested a conceptual model that included hypothesized pathways from prenatal substance exposure to adolescent aggression via autonomic reactivity and violence exposure from infancy to early school age and maternal harshness across early childhood. The sample included 216 families (106 boys) who primarily self-identified as Black or Mixed Race. Results supported the hypothesized path from violence exposure across early childhood and early school age to school age autonomic reactivity and early adolescent reactive aggression. There was also a significant interaction effect of sympathetic and parasympathetic reactivity on adolescent reactive aggression, with sympathetic arousal and parasympathetic suppression at early school age associated with higher reactive relational and physical aggression in adolescence. Results emphasize the importance of early experiences and autonomic nervous system changes in contributing to the cascade of risk for reactive aggression in early adolescence.

Parsing apart affective dimensions of withdrawal: Longitudinal relations with peer victimization.

The current study examined a bifactor model of affective dimensions of withdrawal. Specifically, a model which specified a general factor of anxious-avoidant withdrawal (i.e., withdrawal with negative affect), a specific factor of unsociability (i.e., withdrawal without negative affect), and a specific factor of negative affect without withdrawal was specified in the primary sample (n = 238, 56.3% boys, M age = 44.92 months, SD = 5.32 months) and a validation sample (n = 332, 52.6% boys, M age = 47.11 months, SD = 7.32 months). The model provided a good fit to the data in both samples. In the primary sample, longitudinal relations between the bifactor model and peer victimization were examined across three time points (Time 1 in the spring, Time 2 in the fall, and Time 3 in the spring). Results showed that negative affect without withdrawal was concurrently associated with higher levels of relational and physical victimization at T1, unsociability predicted reductions in relational victimization from T1 to T2 as children entered a new classroom, and anxious-avoidant withdrawal predicted reductions in relational and physical victimization from T2 to T3 as children acclimated to the new classroom. Developmental considerations and clinical implications are discussed.

Measurement of aggressive behavior in early childhood: A critical analysis using five informants.

Measurement of aggressive behavior in early childhood is unique given that relational aggression is just developing, physical aggression is still prevalent, and both forms of aggression are relatively overt or direct. The current study had three aims. The first aim was to examine the internal reliability, validity, and correspondence of five different assessments of aggressive behavior in early childhood: parent report, teacher report, observer report, child report, and naturalistic school-based observations. The second aim was to test a one- and two-factor model of early childhood aggression using confirmatory factor analysis. The final aim of the study was to investigate gender differences among different reports of aggression. Observations, teacher report, and observer (research assistant) report were collected in the children's school, and parent report and child report were collected in a lab session at one time point (N = 300; 56% male; Mage = 44.86 months, SD = 5.55). Observations were collected using a focal child sampling with continuous recording approach, and previously validated measures were used for the remaining four informants. Results demonstrated that all measures were reliable with the exception of child report of relational aggression, and there was small to strong correspondence among the various informants. In addition, a two-factor structure of aggression provided the best fit to the data, providing evidence for divergence among relational and physical aggression. Finally, there were robust gender differences in physical aggression, but gender differences in relational aggression varied by method. The implications of different types of measurement are discussed.

Parental influences on child report of relational attribution biases during early childhood.

Influences on social cognition, such as hostile attribution biases, are a relatively understudied topic despite the association of hostile attribution biases with important developmental and clinical outcomes. From a developmental perspective, it is particularly important to understand the early development of biases regarding how the intentions of others are perceived, especially in the relationship context. Therefore, understanding potential correlates, such as parental influences, of such biases during early childhood may be especially important. The current study (N = 121) was designed to explore several gaps and limitations in the hostile intent attribution literature, especially the lack of research on hostile attribution biases for relational provocations and associated parent behavior. In particular, this gap was addressed by investigating parental influences on hostile attribution biases for relational provocations during early childhood (i.e., 3-5 years of age) using parent and child reports. It was found that parent hostile attribution biases for relational provocations was significantly associated with child hostile attribution biases for relational provocations. Furthermore, it was demonstrated that parent relational aggression was related to parenting practices. Implications for research and practice are discussed.

Relations between forms and functions of aggression and moral judgments of aggressive transgressions.

The present study sought to examine the influence of aggressive behavior, psychopathy, and gender on moral judgments of aggressive transgressions. A two-dimensional conceptualization of aggression was used, such that proactive relational aggression, reactive relational aggression, proactive physical aggression, and reactive physical aggression were treated as distinct subtypes of aggression and also as distinct subtypes of moral judgments of aggression. Participants were 421 emerging adults (215 women). Self-report measures of aggression, psychopathy, and moral judgments were collected. Peer-reports of aggression and psychopathy were obtained from a randomly assigned subsample of 73 participants (46 women) for validity purposes. Unique associations were found between subtypes of aggression and corresponding moral judgments of the same subtypes.

The Reciprocal Relations Between Female and Male Play Partners and Aggression in Early Childhood.

This study examined the relations between male and female play partners (PP) and relational (RA) and physical (PA) aggression in an early childhood short-term longitudinal study (N = 164, Mage  = 47.11 months, SD = 7.37 months). A cross-lagged path analysis was used to examine these relations from Time 1 (T1) to Time 2 (T2), 4 months after T1, and a multiple group analysis was tested across gender. Results showed that T1 male PP predicted an increase in PA, T1 RA predicted an increase in female PP, and T1 PA predicted a decrease in female PP. One path was not equivalent across gender. A post hoc interaction between male and female PP at T1 on future RA was evaluated.

The Influence of Friendships on Aggressive Behavior in Early Childhood: Examining the Interdependence of Aggression.

The present short-term longitudinal study examined the stability and role of peer influence on both physical and relational aggression in early childhood using a dyadic data analytic framework. Following the peer-individual interaction model, forms of aggressive behavior (i.e., physical and relational) were observed in 43 dyads of close friendships in early childhood (M = 47.37 months, SD = 7.56) to better understand how friendships may maintain aggressive behavior over time. Friendship quality (FQ) was included as a moderator to explain how friendships may maintain aggression. The results provide evidence supporting the affiliation hypothesis for physical aggression with opposite findings for relational aggression. Negative FQ moderated associations with both relational and physical aggression over time whereas positive FQ moderated the dyadic influence with physical aggression over time. Limitations and future directions are discussed.

Examining co-occurring and pure relational and physical victimization in early childhood.

The current study took a novel approach to examining peer victimization experiences on a continuum in early childhood. A bifactor approach was used to examine co-occurring victimization as well as the relative contribution of subtypes of victimization, including both physical and relational victimization. To date, no known research has examined co-occurring victimization in early childhood. The fit of a bifactor model, as well as the utility of the model in testing associations with internalizing problems, was examined. The short-term longitudinal study (N=231; 109 girls; Mage=47.46months, SD=7.35) found support for a hierarchical structure of victimization, including co-occurrence and "pure" victimization dimensions, in early childhood. Regression analyses supported that both co-occurring victimization and relational victimization were associated with internalizing adjustment outcomes. These associations differed by gender. A bifactor model may be a useful statistical technique to address the common finding of co-occurrence of victimization to better understand peer harassment experiences and risk for adjustment problems.

Testing a Higher Order Model of Internalizing and Externalizing Behavior: The Role of Aggression Subtypes.

This study assessed how the forms and functions of aggression fit into a higher order model of internalizing and externalizing behavior, for children in early childhood (N = 332, M age = 47.11 months, SD = 7.32). The lower order internalizing factors were depressed affect, anxious-fearfulness, and asocial behavior (i.e., social withdrawal) and the lower order externalizing factors were deception and hyperactivity. The forms and functions of aggression were crossed to create four factors: reactive relational, reactive physical, proactive relational, and proactive physical aggression. Seven confirmatory factor models were tested. Results supported a two-factor externalizing model where reactive and proactive relational aggression and deception loaded on one externalizing factor and reactive and proactive physical aggression and hyperactivity loaded on another externalizing factor.

Prospective associations between peer victimization and social-psychological adjustment problems in early childhood.

The present short-term longitudinal study examined prospective associations between two forms of peer victimization (i.e., physical, relational) and both externalizing and internalizing problems in early childhood. The study assessed 97 children (42 girls; M age = 45.22 months, SD = 6.99) over the course of one school year with assessments occurring at the end of each semester (approximately 6 months apart). Multiple methods were used to collect data over the course of one school year to test theoretically driven hypotheses. Cross-lagged path analyses were conducted, revealing significant associations between relational victimization and increases in depressive symptoms. On the other hand, relational victimization was also significantly associated with decreases in externalizing problems (e.g., inattention, deception/lying) and increases in prosocial behavior. Physical aggression predicted increases in physical victimization, supporting hypotheses that children displaying physically aggressive behavior are likely to be reactive to negative peer interactions and endure future victimization.

Relational Aggression, Victimization and Self-Concept: Testing Pathways from Middle Childhood to Adolescence.

When studying adolescent development, it is important to consider two key areas that are salient for teens, which are self-concept and peer relations. A secondary analysis of the National Institute of Health and Human Development Study of Early Child Care and Youth Development was conducted to examine the prospective bidirectional associations between self-concept and peer relations. To date, how social development broadly and peer relations in particular (e.g., relational aggression and victimization) affect self-concept domains is not fully understood. Using a large sample (N = 1063; 532 girls; M = 11.14 years; SD = .59) with multiple informants, the present study examined whether fifth grade relational aggression and sixth grade relational victimization was associated with adolescent self-concept in three key domains (i.e., academic, sports, physical appearance). A significant direct effect emerged, such that relational aggression in middle childhood was associated with decreases in academic self-concept and increases in sports self-concept in adolescence. Analyses also revealed that having higher levels of domain specific self-concept led to decreases in relational aggression across the transition to adolescence. The findings highlight the importance of examining bidirectional prospective associations between relational aggression, relational victimization, and domain specific self-concept. Implications for future research and clinical intervention are discussed.

Future directions for research on the development of relational and physical peer victimization.

After several decades of research on peer victimization and associated constructs the field is poised to make a number of important discoveries and advances. More specifically, the study of peer victimization subtypes has rapidly increased since the seminal work of Crick and Grotpeter ( 1996 ) on relational and physical victimization. The current state of the field is briefly reviewed, and recommendations for future directions are provided to advance our literature. Critical future directions are discussed and include (a) broaden the range of adjustment outcomes and examine differential pathways associated with physical and relational peer victimization; (b) study peer victimization subtypes at multiple levels of influence including psychophysiological and gene-environment interactions; (c) study physical and relational victimization outside of friendships and links with other close relationship systems; (d) examine the role of culture on peer victimization subtypes; (e) focus on context including but not limited to socioeconomic status; (f) test the role of gender, gender identity, and gender-linked self-construals; (g) explore the impact of peer group processes; and (h) continue to develop evidence-based programs for physical and relational peer victimization. Finally, the adoption of a developmental psychopathology framework is stressed as a means by which we may advance our future study of peer victimization subtypes.